It is often desired to utilize a fluid, such as water, as part of a display or attraction. Increasingly, the popularity of using water attractions as an integral part of domestic and commercial landscaping has moved architects and landscapers to push further and further into incorporating the decorative aspects of these water features into new building and sites. These features are incorporated through swimming pools, spas, ponds, lakes and other water features and sources found in the typical property. Various types of fountains adorn public and private plazas, parks, advertisements, and amusement parks.
To this end, recent interest and developments have been made in producing smooth, laminar flows of water which give the appearance of a solid glass or clear plastic rod in various water attractions, for instance, the fountain presentation in the Bellagio Hotel in Las Vegas or the Dancing Frogs attraction at the EPCOT center of Disney World, as described in U.S. Pat. No. 5,078,320 to Fuller, et al. These attractions incorporate laminar flow water jets. These devices jet water like a fountain, but the water has a minimum of turbulence in it, that is the water is predominantly laminar. This results in the smooth rod structure of the streams that are issued from the jets.
These devices have used a wide variety of elements to instill laminarity into the water flow. Various attempts have been made at reducing laminarity with a variety of elements in a water stream. For example, U.S. Pat. No. 4,393,991 to Jeffras et al. discloses a water nozzle which utilizes an elongated conical nozzle which includes fin-like members to reduce the turbulence of the water and to produce a laminar flow in the water. U.S. Pat. No. 3,321,140 to Parkison et al. discloses an attachment for a faucet which utilizes a series of fins in a cylindrical nozzle for producing a laminar flow of water to reduce the splash on the bottom of a sink or tub. U.S. Pat. No. 3,730,440 to Parkison teaches a laminar flow spout which utilizes a plurality of independent nozzles arranged within the single spout which results in a plurality of streams having laminar flow characteristics.
Other methods which have been utilized to obtain laminar flow of fluids include the use of curved perforated disks inserted in the jet to produce a splashless laminar output, such as in U.S. Pat. No. 3,851,825 to Parkison et al; U.S. Pat. No. 3,630,444 to Nelson; and, U.S. Pat. No. 3,730,439 to Parkison. In U.S. Pat. No. 4,119,276 to Nel, for instance, a plurality of straight, perforated screens having varying degrees of perforation are utilized to provide a splash free, clear, laminar output. Further variations in the designs of the screened or filtered embodiments provide for foam screening filters. For instance, U.S. Pat. No. 4,795,092 to Fuller; U.S. Pat. No. 4,889,283 to Fuller et al.; and U.S. Pat. No. 5,213,260 to Tonkinson show closed cell foam screens or filters, similar in positioning and function to the screens shown in the previously discussed devices. The overarching goal of these screens is to reduce turbulence in the movement of water stream within the water jet. However other sources of turbulence exist beyond the simple flow of the water.
For instance, another significant source of turbulence in the water stream occurs from pump surges and overpressures associated with variations in pump operation. Several design features have been attempted to mitigate such variations. For instance, some designs feature a first outer chamber for initial input of water which slows the water and accommodates surges. Air pockets are also often provided within a housing to accommodate any overpressures and reduce the turbulence. For example, in U.S. Pat. No. 5,641,120 to Kuykendal et al., the water is first passed into an outer chamber then passed radially into a second chamber. Within the second chamber the water is filtered through a series of screens/baffles to reduce turbulence and improve laminarity prior to being ejected from a nozzle to produce a laminar jet. The system accommodates pump surges and pressure variations by using a larger, more complex housing comprising of a first and second chamber. This adds costs and complexity to the system and requires a larger footprint, potentially limiting the application of the device in some landscape situations.
Similarly, various attempts have been made to provide surge suppressors in pipes and piping systems. For instance, U.S. Pat. No. 2,495,693 to Byrd, et al.; U.S. Pat. No. 3,473,565 to Blendermann; U.S. Pat. No. 5,718,952 to Zimmerman, et al.; and U.S. Pat. No. 6,390,131 to Kilgore show surge suppressors used in piping systems. U.S. Pat. No. 4,732,175 to Pareja shows a surge suppressor including a rigid outer housing and a tubular diaphragm member placed coaxially within a rigid outer housing. The member is made of a suitable elastomeric material having predetermined durometer and elastic properties.
However, unlike these piping systems, in a laminar flow water jet besides mitigating pressure variations and pump surges, the goal is to reduce the turbulence in the water. Placing a surge suppressor like this in the line prior to the body of the laminar flow water jet may help to accommodate some of the turbulence and overpressure associated with a surge, but this is minimal due to the limitations in the degree of change in the narrow volume of the hose relative to the total volume of water passing through the jet. Furthermore, with the distance between the surge suppression device in a hose and the point at which the flow enters a jet, the suppression device may introduce further turbulence immediately prior to the intake as there is significant axial and/or radial motion in the velocity profile at the water intake due to the variation of the hose volume. In fact, depending on the elastomeric properties, the deflection of the water flow within the surge suppressor may even attenuate these turbulences. As a result, eddies and turbulences may be carried through the jet and result in an output which includes undulations, splashing, and ripples.
As an example, U.S. Pat. No. 5,160,086 to Kuykendal et al. incorporates a surge suppression device in the input hose of a laminar flow water jet system. It describes a lighted laminar flow nozzle with a resilient hose and a bladder. As discussed above, due to the placement and distance of the resilient bladder from the inner housing, it does not allow for adequate laminarity to develop in the flow. Therefore, the design incorporates a diffuser element, a first and second chamber, a series of screens, and an air pocket to mitigate the inability of the bladder alone to both accommodate the pump surges and provide additional laminarity in the flow. This increases the cost, complexity, and size of the resulting device.
Although these prior methods are useful in reducing the amount of turbulence in streams of water and accommodating pump surges, none of the methods or devices to date is suitable in providing a laminar flow water jet with a single chamber, with improved laminarity and reduced size, wherein substantially all of the turbulence is eliminated from a columnar stream of water as it exits the water jet. Thus, there exists a need to provide a laminar flow water jet with the ability to adequately accommodate pump surges and pressure variations while providing for improved laminarity within the device and simultaneously minimizing the overall size and complexity of the device to reduce costs and improve flexibility for landscaping by reducing the overall footprint of the device.